Witches' Cave, Limestone cave in Malargüe Department, Argentina.

Witches' Cave is a limestone cave system located within a provincial reserve at approximately 1,830 meters (6,000 feet) elevation in the Andes. The site features stalactites, stalagmites, and underground pools formed by water erosion over geological time.

The cave formed during the uplift of the Andes, when underground water currents carved through Jurassic sedimentary rock. This geological process occurred over millions of years as the mountain range rose.

The name comes from local legends: two white women held captive in the cave were said to have turned into birds through witchcraft rituals. Another version attributes it to the strange shadows cast on the gallery walls by firelit ceremonies. Many rural residents still avoid exploration activities because of this supernatural perception.

The cave sits on Moncol Hill at 1,830 m, about 65 km southwest of Malargüe; access is via RN 40 plus an 8 km access road, with Bardas Blancas the nearest settlement. Guided visits with helmets and lamps cover only the first 200 m of galleries, which are already damaged. The interior is cool and damp, so wear sturdy shoes.

The cave's explored passages total about 6 kilometres, yet visitors only enter the first 200 metres of galleries. Around the entrance, exposed strata hold fossil evidence of gastropod molluscs from the Jurassic and Cretaceous periods, a detail most walk past on the way in.